1. Field of the Invention
The present invention relates to a safety device for fluid transfer systems and, more particularly, to a safety device operable in response to detection of a predetermined negative pressure level in one or more intake lines of a fluid transfer system to eliminate a vacuum therein, thereby removing a suction force at the open ends of the intake lines.
2. Description of the Related Art
Drowning is the second leading cause of unintentional injury related deaths to children 14 years old and younger. While most drownings occur in swimming pools, a surprising fact is that in many swimming pool and hot tub drownings (both adults and children), the main culprit is the water circulation system. In a typical pool, the circulation system includes a main drain suction intake line and at least one skimmer suction intake line, both of which feed into a main intake line that leads to a pump. A return line directs water flow back into the pool.
Most people do not feel threatened by a pool's circulation system, including the main drain intake on the bottom of the pool, and the skimmer boxes along the side of the pool. However, if a person comes into contact with any of the suction intake lines of the circulation system (at either the main drain or skimmer intakes) causing the suction intake to be covered or obstructed, the immense suction of the pump forms an instant seal between the open end of the suction intake line and the person's skin or clothing. This may result if a person places their hand over the open end of the suction intake line or, as often happens with children, a person sits down on the suction intake. In either case, the force needed to pull them free often exceeds 800 pounds. Moreover, the injuries which are inflicted in a matter of a few seconds are horrific, usually permanent and sometimes fatal. If a person, especially a child, is sucked onto the main drain suction intake on the bottom of the pool, they usually drown.
The only way to free a person sucked onto the intake of a circulation system of this type, without causing severe injury or dismemberment, is to interrupt or disable the source of the suction force, i.e., the pump. This can be done by interrupting power to the pump. However, even if the pump is shut down, a vacuum will remain in the intake side of the system between the pump and the obstructed end of the suction intake line. Nonetheless, a victim could still be freed with some assistance, causing minor injuries. Ideally, if the vacuum in the intake line can be quickly eliminated after a victim becomes stuck to the intake, the victim will be freed with little or no assistance and without injury.
In most instances wherein a victim becomes stuck to an intake of a circulation system, typically in a swimming pool or hot tub, rescuers fail to realize the need to immediately shut off the pump. Instead, in a panic, people tend to go to the victim and attempt prying them free. In the rare instance this is successful, the injuries are often severe and permanent. Of course, there are also instances wherein there are no other people present to come to the victim's rescue. These situations are almost always fatal.
The imminent danger presented by fluid circulation systems of the type commonly found in swimming pools, hot tubs, and the like has been longstanding in the art. Little, if any, attention has been given to providing a satisfactory solution to this deadly problem that exists in every swimming pool, hot tub, as well as all other fluid circulation systems wherein a fluid is drawn from a reservoir through one or more suction intakes by a pump. Accordingly, there has been and there remains an urgent need to provide an effective means of preventing death and injury to those otherwise unfortunate victims who become unexpectedly attached by suction to the intake of a fluid circulation system.